The structure and quantitation of Urinary Basement Membrane Glycoprotein in Normal and Diabetics: Although one reported defect in diabetes has been in basement membrane structure, little opportunity has been realized toward comparing amino acid sequences in these important proteins in diabetics and normals. This approach has been difficult because of the insoluble nature of the basement membrane collagen. We have discovered urinary fractions which are rich in soluble fragments of basement membrane collagen. One fragment has been purified, the amino acid composition determined, and the first 18 amino acids in its sequence determined. Many more of these basement membrane fragments will enable us to compare diabetic and normal membrane structures. Another result from this research will be the preparation of antibodies to quantitate the amount of basement membrane excreted in the urine of normals and diabetics. This may be important in the diagnosis and/or monitoring the disease.